JPS62128035A - Photosensitive medium and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to photosensitive media using organic charge transfer materials, and more particularly to various enhancement mechanisms for enhancing thermal/optical erasing properties.

[Conventional technology]

With the advent of the information revolution, research activities have recently focused on the development of optical storage media. Currently, optical memory devices use photochemical hole burning (PIIB), which uses a laser to form pits in a material to store data.
) has become mainstream. In Applied Physics Letters Volume 11, Issue 40 (published June 1, 1982),
A Japanese article by J. J. Wroble et al. has been published under the title “Laser Marking of Organic Thin Films,” which describes a technique for burning holes in organic thin films using a laser beam. Similarly, in Applied Physics Letters Vol. 11, No. 41 (published July 1, 1982), Mabosch et al. reported on optical writing on a blue iridium oxide film formed by sputtering. There is.

This technique uses an optical writing mechanism to thermally induce dehydration at temperatures below the melting point of the optical medium.

U.S. Pat. No. 3,983,542 to Ovshinsky discloses a material that undergoes a physical change from an amorphous state to a crystalline state upon receiving a beam of light.

Furthermore, 5 of the Journal of Applied Physics
0(3) (published in March 1979) by Nabotny (No.
votny et al., which describes a diffusion-based optical marking process in a dye-polymer system.

Prior art optical memory systems have one significant drawback, namely that the storage medium is non-erasable.
As a result, optical memory technology has not been applied to computer engineering requiring read, write, and erase functions.

Potember (R, S, Potember), Baler
(T, 0° Poehler) and Cowan (D, 0.
Cowan) disclose organic charge transfer salts, such as CuTCNQ, that exhibit stable and reproducible switching between an equilibrium state or a first state and a second state in the presence of an electric field.

The above patents are (1) U.S. Pat.
Application No. 385.523 filed on May 7, 2007, entitled "Method for Manufacturing Current Controlled Bistable Electrical Organic Thin Film Switching Device".

The organic charge transfer salt undergoes a reversible electrochemical topotactinocredox reaction under the action of an electric field, changing from a first state to a second state.

An identifiable change in impedance occurs between the equilibrium or first state and the second state after switching.

In particular, an electric field is applied across a thin film of CuTCNQ or similar organic charge transfer salts. When this electric field exceeds a threshold, the impedance across the organic thin film decreases from a relatively high impedance to a relatively low impedance.

Two papers by Potember, R.S. et al. report that organic films electrically switch to an equilibrium or second state with different optical properties than the first state.

The above paper is (1) Chemi-Riki Suflipta Volume 17, 21
9-221 (1981), "Wave and X-ray photoelectron spectra of copper-TCNQ semiconducting films" and (
2) ``Electrical Switching and Memory Phenomena in Semiconducting Organic Thin Films'' described in American Chemical Society Symposium Series No. 184 (1982), which describes infrared spectroscopy means and also Reference is made to Raman spectroscopy techniques (Matsuzaki et al.). This reference is entitled 'Raman spectra of conducting TCNQ salts', published in Solid State Communications, Volume 33, pp. 403-405 (1980).
describes a technique for determining whether a switched CuTCNQ film is in a first state or a second state by the application of a DC or AC electric field. In a follow-up study, Kamitsos et al. (E. 1. Kamitsos et al. It explains. This research report is published in Solid State Communications, Vol. 42, No. 8, 561, entitled “Raman analysis of electrical switching mechanisms in CuTCNQ films.”
-565 (1982). The above papers all discuss CuT switched by applying an electric field.
Whether the CNQ area is in the first state or the second state,
It is pointed out that it can be identified using spectroscopic means.

Bohtemper (R, S, Potember), Boehler (T, 0° Poeh 1er) and Benson (
U.S. Patent Application No. 464,771 filed February 7, 1983 by R.C.
teaches that in the presence of light energy, organic charge transfer salts undergo a redox reaction and switch from a first state to a second state, each having its own detectable light spectrum. Whether a particular spot on the storage medium is in the first (first neutral) or second (post-switch) state can be determined optically by spectroscopic means. This application further teaches that the application of thermal energy can reverse the electrochemical reaction and return the material to a first (neutral) state.

Ultimately, the above application teaches an actuated photosensitive medium that can be switched and erased by an optical beam on a section-by-section or bit-by-bit basis.

Applied Physics Letters Volume 41 No. 6 (19
A sentence by Botenper, Boehler, and Benson published under the title "Optical Switching in Semiconductor Organic Thin Films" (September 15, 1982) and Soli Nodo State Communications, Vol. 45, No. 2 (1983)
An article by Kamitos and Reissen (W, M, R45en, Jr.) published under the title "Photoinduced Transformation of Metallic TCNQ Materials" in 2003 discusses the optical switching properties of organic charge transfer salts. 1 by boat tempering and baler
U.S. Patent Application No. 603,71 filed April 25, 1984
No. 7 (Title of the invention: Multi-state optical switching and memory using amphoteric organic charge transfer materials) is a technology in which an organic charge transfer material is switchable to multiple states, and a multi-bit memory at each spot on an optical storage medium. We will teach you how to make it possible.

Although the above references teach the use of organic charge transport materials in photosensitive media, there remained a need to improve the reproducibility of the erasure process.

Erasing cycles of 10"-106 bits are desired for erasable optical storage disks that meet the demands of the current data processing industry.

[Means for solving problems]

Applicants have discovered that the erasure properties of organic charge transfer switching materials are improved by the enhancement mechanism described herein. This enhancement mechanism primarily provides a secondary source of component moiety molecules in a neutral state or in an altered oxidized state. Placing molecules of such component moieties in close proximity to the switched organic charge transfer material promotes thermal recombination of the switched material. For example, if an organic charge transfer salt such as CuTCNQ is the switching material, according to the invention:
A secondary source of neutral receptor TCNQ' molecules is provided. The present invention further teaches that the use of complexing or chelating agents enhances the compatibility of various component moieties in neutral or altered oxidation states and promotes thermal/optical recombination. It is something to do. For example, if the complexing agent is Cu
It helps solubilize the ion-radical salt of TCNQ and enhances its compatibility with another constituent neutral receptor molecule, TCNQ'.

In a first embodiment of the invention, a thin film of organic charge transfer switching material deposited on a supporting substrate comprises a neutral moiety molecule (e.g., a neutral acceptor molecule) in an optical complexing agent.
coated with a polymer dispersion containing. Neutral receptor molecules and complexing agents are interspersed within a polymer matrix forming a solid transparent coating layer. Enhanced thermal quenching is observed at the interface between the polymer dispersion and the organic charge transport material thin film upon application of the light beam used to generate thermal energy. In a second embodiment of the enhancement mechanism according to the invention, the polymer dispersion comprises an organic charge transfer switching material (e.g., microcrystals of the organic charge transfer salt CuTCNQ) and a reinforcing material (e.g., neutral component acceptor molecules, TCN
Q') and both are interspersed. Optionally, the polymer dispersion may be interspersed with a complexing agent to enhance compatibility between the switched moieties. A thin film of the polymer dispersion may be coated onto a supporting substrate, or the polymer dispersion may be formed into a suitable shape (ie, a disc, record, etc.) to provide a self-supporting substrate.

Various applications of the enhancement mechanisms taught by the present invention improve the cancellation characteristics of switching materials. A variety of organic charge transfer materials can be used, including two-state and multistate amphoteric charge transfer materials.

A moiety molecule in a neutral or altered oxidation state can act as a donor and/or if a two-state switching agent is used.
or a neutral receptor molecule, one or more neutral, reducing or oxidizing moieties of an amphoteric compound if a multistate switching agent is used.

Accordingly, a first object of the present invention is to provide an enhancement mechanism that improves the erase characteristics of organic charge transfer switching materials.

This enhancement mechanism provides a secondary source of at least one moiety molecule of the switching substance in a neutral or altered oxidation state, thereby promoting thermal recombination. A second objective of this invention is to increase the compatibility of various component moieties in a switched state using complexing or chelating agents (e.g. complexing agents enhance the solubilization of ion-radical salts). and increase its compatibility with neutral receptor moiety molecules). A third object of the invention is the use of a polymer matrix as a coating layer covering a thin film of organic charge transport material. This coating layer is a polymeric matrix interspersed with reinforcing substances (eg, neutral molecules of receptor moieties) and interspersed with optical complexing agents. A fourth object of this invention is the use of polymer dispersions.

The polymer dispersion comprises a polymer interspersed with microcrystals (or powders) of an organic charge transfer switching material, molecules or atoms of a component moiety of neutral or other altered oxidation state, and an optical complexing agent. matrix (e.g., if the organic switching substance is CuTCNQ, the reinforcing substance would be the neutral receptor molecule TCNQ'')
. A fifth object of this invention is to protect organic charge transfer switching materials and to reduce migration or sublimation of component moieties (e.g., donor and acceptor species) during the switching process. The solution is to use internal confinement. A sixth object of this invention is to use a self-supporting switching polymer dispersion that reduces manufacturing costs and simplifies construction of optical switching media.

The above and other objects of the invention will be readily understood from the following description of some illustrative embodiments with reference to the accompanying drawings.

〔Example〕

First, in order to facilitate understanding of the enhancement mechanism according to the present invention, we will refer to currently pending U.S. Patent Application No. 464,77.
Some of the principles of optical switching described in 1. Title of the Invention: Optical Storage and Switching Devices Using Organic Charge Transfer Salts are described herein for reference.

The redox reaction that occurs when a bistable organic charge transfer salt such as CuTCNQ is irradiated with a light beam with sufficient optical field strength and switches from a first state to a second state is shown below.

Light energy (M” (TCNO”)), l # M”,
+ CM"(TCNQ")) , -,
+ (TCNll).

1st state 2nd state ・・・・・・(
1) The reason why the above switching occurs is that the light beam (i.e. optical band electromagnetic field strength) breaks the bond between the organic electron acceptor (TCNQ in this case) and the donor (denoted by M), and the charge is transferred from the donor to the organic This is because they begin to move to electron acceptors.

The change in charge distribution when the organic salt switches from the first to the second state is clearly illustrated by equation (1) above. 1st
In the or ground state, the organic electron acceptor moiety exists almost exclusively in the reduced form (TCNQ''), but in the second or post-switch state, it exists in the reduced form (TCNQ=) and the neutral form (TCNQ''). ) exists in the form of an image.

As can be seen from equation (1), each state is associated with a unique combination of redox species. In the first state, the receptor moiety is almost exclusively in the reduced form (
For example, TCNQ = only molecular species exist), but
After the switch or in the second state, the receptor moieties have reduced and neutral picture forms (e.g., TCNQ= and TCNQ
'Molecular species exist). Visual observation, spectroscopy, fluorescence,
and/or other optical means to determine whether the two-state charge transfer salt is in the first or second state by identifying the optical properties associated with each redox species. .

FIG. 1 shows the Raman spectral bands of the organic charge transfer salt CuffCNQ.

Figure 1a shows the spectral bands of neutral TCNQ (eg TCNQo) (note: Raman band (10) at 1451 cm-'). Figure 1b shows that substantially all organic electron acceptor moieties are present in reduced form (e.g., T
CNQ" shows the spectral bands of CuTCNQ in the first (pre-switch) state (where only redox species are present) (note: Raman band at 1375 cm-' associated with TCNQ" (12)). Figure 1c shows that the organic electron acceptor moiety exists in both reduced and neutral oxidized states (TCNQ'' and TCNII' molecular species exist).
(or after switch) shows the spectral bands of CuTCNQ in the state (Note: 1375 cm −' (10
) and 1451 cm −' (12) where Raman bands appear). The Raman spectral band is the fundamental absorption mode that senses the oxidation state of the organic electron acceptor moiety, which clearly identifies the redox species present (i.e., in this example, the TC
NQ or TCN [the presence of the 1' redox species is determined]. When CuTCN(l) is used as an organic charge transfer salt, one only needs to analyze the spectral band (10) at 1451 cm to determine whether the organic salt is in the first or second state. Can be done.C
If the uTCNQ organic charge transfer salt is in the first state, 145
The spectral intensity at 1 cm-' is low, and if the organic charge transfer salt is in the second state, it is 1451 cm-' (1
The spectral intensity at 0) is high.

As mentioned above, there are many organic charge transfer salts that switch from a first state to a second state upon irradiation with a light beam. various TCs
FjQ derivatives are complexed with metal electron donors to form organic charge transfer salts capable of photoswitching. Incidentally, these TCNQ derivatives are listed below.

TCNQ(OMe) TCNQ
IMeTCNQ(OMe)z
TCNQ ITCNQ (OMe) (OIE t
) TCNQ (OMe) (OCIl, J)
zTCNQ(OMe)(0-i-Pr) TC
NQ(CN)zTCNQ(OMe)(0-4-Bu)
TCNQ(Me)TCNQ(0-+-CJs)
TCNQ(Ht)TCNQ(OEt)(S
Me) TCNQ (i-Pr) TCNQ
CI TCNQ(i-Pr)zTCN
Q Br TCNQ CI Me TCNQ Br Me Furthermore, an organic charge transfer salt complexed from an organic electron acceptor and a donor containing at least one cyanomethylene functional group also has photomemory and photoswitching functions.

Furthermore, it has been found that organic salts consisting of complexes of organic electron acceptor and donor moieties containing at least one kiln unit also have similar photomemory and photoswitching functions. Specifically, organic salts formed from the organic electron acceptors listed below have optical memory and/or optical switching functions. They are tetracyanoquinodimethane (TCNQ).

Tetracyanonafuquinodimethane (TNAP).

2.3 dichloro-5,6 dicyano 1.4 Benzoquinone (DDQ).

Tetracyanoethylene (TCNE).

Hexacyanobutadine (IIcBD).

11.11,12.12-tetracyano-1,4 naphthoquinodimethane (BenzTCNQ).

2,5-bis(dicyanomethazine)-2,5-cybaidorothiophene.

2,5-bis(dicyanomethazine)-2,5-selenophene.

Thiophene-(T)-TCNQ.

(Selenophene-(Se)-TCNQ).

Tetracyanoquinoquinazolinoquinazoline (Te3 mouth)
.

Hexacyanotrimethylene cyclopropane (HMC
TMCP).

2.4-bis(dicyanomethylene)-1,3-dichetane (BDDT).

Also, any of the above TCNQ derivatives.

An organic salt consisting of a complex of the metal listed below and any of the above organic electron acceptors has a light switching function. These metals are copper, silver, lead, nickel, lithium, sodium, potassium, barium, chromium, molybdenum, tungsten, cobalt, iron, antimony, cesium and magnesium. Furthermore, organic salts consisting of a complex of an organic substance acting as a donor and an organic electron acceptor listed below also have optical memory and/or optical switching functions. These are tetrathioethylenes,
These are dithiozine aminoethylenes, dithiodisalinoethylenes, tetraaminoethylenes, azenes, and hydrocyclic aromatics.

It should be noted that organic charge transfer salts other than the above consisting of organic electron acceptors having either a cyanomethylene functional group or a kiln unit, or other organic salts with similar characteristics, change from the first state to the first state when irradiated with light. Note that there is a two-state switch.

As can be seen from equation (1), this electrochemical reaction can be thermally quenched.

Application of thermal energy to an area of the organic charge transfer salt chemically binds the donor and electron acceptor neutral molecules in the second (post-switch) state and returns them to the first state. A reversible reaction, a thermally activated process, returns the material to its lower energy state. The applied heat can be generated by electrical or optical/thermal means.

Preferably, the thermal energy is generated by a laser. It has been found that when a CO2 laser with an intensity below the switching threshold is focused on a certain position and this alignment is maintained for a suitable period of time, the generated thermal energy switches the position and returns to the first state.

The present invention is intended as a means to improve or enhance the erasing properties of photosensitive organic charge transfer media to produce photosensitive media that can be switched and erased repeatedly. The enhancement mechanism according to the present invention provides a secondary source of neutral molecules for the electron acceptor and/or donor component of the organic charge transfer salt, improving the speed and reproducibility of erasure. 2 of this invention
One generalized embodiment takes advantage of this enhancement mechanism.

[Multi-layer enhancement implementation]

The multilayer enhancement embodiment shown in FIG. 2 involves applying a thin film (14) of an organic charge transfer salt on a supporting substrate (16) and then applying this thin film (14) to an auxiliary neutral salt in an optional complexing agent. It is coated or coated with a polymer dispersion (18) containing receptor molecules. Techniques for complexing organic salts from donor and acceptor moieties and forming thin films are described, for example, in U.S. Pat. and switching devices), and in U.S. Patent Application No. 385.523 (title: Method of Making Current Controlled Bistable Electrical Organic Thin Film Switching Devices). Other well-known chemical methods exist, such as coating, sputtering, and vapor depositing thin films onto a substrate.

The coating thin layer containing the enhancement mechanism is first coated with neutral acceptor molecules (the same type of acceptor molecules used to complex certain organic salts) in a thermostable polymer matrix.
After mixing to form a dispersion, this dispersion is prepared by coating on a film of an organic salt. The covering layer forms a relatively transparent polymeric matrix interspersed with neutral molecules of the receptor compound. At the interface between the polymer dispersion and the organic charge transfer material coating, enhanced or improved thermal extinction is observed upon irradiation with a light beam for generating thermal energy.

The reason for this enhanced quenching is that the excess neutral acceptor molecules of TCN (1°, etc.) in close proximity to the neutral donor ion are recombined and immediately form the original charge transfer complex. The erasing properties of the photosensitive medium are further enhanced if complexing or chelating agents are further interspersed within the coating layer.To prepare such a coating layer (18), neutral acceptor molecules are The complexing agent or chelating agent is mixed with the thermostable polymer matrix to form a dispersion. The dispersion thus formed is then coated onto the organic charge transfer composite membrane (Step 4). The effect is to increase the compatibility between the neutral acceptor molecules interspersed in the polymer matrix and the donor atoms present in the switched parts of the organic charge transfer membrane.

Other possible coating layers (18) include, for example:
Instead of interspersing neutral acceptor molecules in the dispersion, neutral donor atoms or molecules may also be interspersed. Optionally, the dispersion may be mixed or dispersed with neutral molecules of both donor and acceptor moieties. Additionally, the polymer matrix must allow light energy to pass through the covering layer (18) and reach the charge transfer membrane (14) where switching occurs. The use of transparent heat stable polymer matrices is preferred in this regard. The process of applying the coating layer (18) to the organic charge transfer film may involve spin casting, brushing, UV curing, spraying or dry coating, and the like. Optionally, the dispersion may be formed (injection molded or otherwise) into a thin layer. This thin layer is then pressed and bonded onto the organic charge transfer membrane (14) to form a fixed covering layer. Additionally, a solvent may be included in the dispersion to aid in the coating process. After coating the dispersion onto the organic charge transfer membrane, the solvent is evaporated to form a solid coating layer.

The functions performed by the coating layer (18) are listed below.

(1) Excess neutral acceptor molecules that are interspersed or mixed into the polymer matrix serve as a secondary source of molecules that combine with donor atoms or molecules during the quenching step.

(2) neutral receptor molecules with complexing agents interspersed in the dispersion;
Enhances compatibility with donor atoms or molecules present in the switched portion of the organic charge transfer membrane.

(3) The polymeric protective film protects the organic charge transfer film and acts to reduce migration or sublimation of the donor or acceptor species during the switching process.

An example of a multi-layer enhancement implementation will now be described.

Approximately 40 mg of neutral TCNQ (neutral receptor molecule)
500 mg polymethyl methacrylate (polymer matrix) in 00 ml dichloroethane (solvent)
and 250 mg of polyethylene oxide (complexing agent). This solution is stirred to obtain a homogeneous clear slurry. This dispersion was then combined with CuTCN
It is poured or layered onto a substrate containing a thin film of loss-switching material.

The polymer matrix in which the excess neutral TCNQ molecules are dispersed forms a transparent flexible film on the switching material.

The solvent (dichloroethane) is blown off the polymer dispersion and a solid film is formed.

Various matrix polymers can be used, examples of which are listed below.

Polycarbonate polymethyl methacrylate (PMMΔ) polyacrylonitrile polyvinyl acecool poly(methyl-2-cyanoacrylate) poly(4,4
”Isopropyridine-diphenyl carbonate) (L
exan) polystyrene poly(pyromellitimide) (Kaptan) poly(vinyl fluoride) ethyl cellulose poly(ethyl acrylate) poly(methyl acrylate) as well as mixtures of any of the above. Various complexing or chelating agents may be used; Examples are listed below.

Acetylacetone and its derivatives Polyethylene oxide (Carbowax) Polypropylene glycol Polymer Quaternary ammonium salt Crown ether Poly(butylene glycol) Poly(epichlorohydrin) Ethylenediaminetetraacetic acid (EDTA) Nitriloacetic acid (NT^) Dimethylglyoxime (DMG) ) Organic charge transfer salts can be complexed from the non-limiting groups of acceptor and donor molecules described herein above.

Also, the acceptor or donor (of the type that complexes the organic salt) may be dispersed in the matrix polymer.

[Single reinforcement layer switching material]

A second embodiment of the invention, illustrated in Figure 3, comprises an organic charge transfer salt (as a powder or microcrystals) and an auxiliary neutral acceptor molecule (of the same type as the acceptor molecule used to complex the organic salt). , and the matrix polymer are mixed together to form a single polymer dispersion. Polymer dispersion (20) is a switching substance! (organic charge transfer salt)
and the reinforcing substance (24) (neutral receptor molecules) form a monolayer interspersed with both. A thin film of polymer dispersion is coated onto a supporting substrate. Alternatively, the polymer dispersion may be formed into a suitable shape (such as a disc or record shape) to provide a self-supporting substrate. The use of polymer dispersions formed as self-supporting substrates eliminates the complex vacuum techniques required to manufacture optical recording media. The availability of a secondary source of neutral acceptor molecules interspersed within the matrix polymer in close proximity to the donor atoms generated locally by photoinduced electrochemical switching reactions improves or enhances the scavenging properties. Thermal energy reverses the reaction and the acceptor or co-neutral acceptor molecule that was bound to the organic salt recombines with the donor atom or molecule to a lower energy state.

Interspersing a complexing or chelating agent (25) within the polymer dispersion further enhances the erasing properties.

To prepare such polymer dispersions, switching substances (powders or microcrystals of organic charge transfer salts), reinforcing substances (
(a neutral molecule of an organic receptor) and a complexing agent. This results in the formation of a single polymer dispersion. The polymer dispersion is then formed into a coating on a substrate or to form an optical storage disc or record or the like. Complexing agents enhance the uniformity of the dispersion by reducing microcrystallization of the neutral acceptor molecules. The complexing agent further assists in the solubilization of the ion-radical salt and increases its compatibility with the neutral acceptor molecule. Both of these factors enhance the heat dissipation properties of the material. Other single polymer dispersion embodiments are also contemplated. For example, instead of interspersing neutral acceptor molecules as reinforcing agents in the polymer dispersion, neutral donor atoms or molecules may be interspersed. Alternatively, the polymer dispersion may be mixed or interspersed with neutral molecules of both donor and acceptor moieties.

Furthermore, although the polymer matrix requires the ability to pass light energy, the use of transparent, heat-stable polymer matrices is preferred. The process of coating the polymer dispersion onto the substrate can utilize spin casting, brushing, spraying, or dry coating.

Alternatively, the polymer dispersion may be molded (by injection molding or otherwise) into a thin layer and pressed onto the substrate. Additionally, a solvent may be added to the polymer dispersion to assist in the coating process. The solvent may be evaporated after coating the polymer dispersion onto the substrate. If a simple non-erasable disk is desired, a powder or microcrystals of an organic charge transfer salt may be mixed into a polymer matrix to form a switching dispersion. The switching dispersion may be coated onto a substrate or separately molded to form a self-supporting substrate.

An example of a single enhancement layer switching material will now be described.

Approximately 500 μ of CuTCNQ powder is mixed into a slurry containing 50 μ of neutral TCNQ, 500 μ of polymethyl methacrylate, and 250 μ of polyethylene oxide in 200 ml of chloroethane. This solution is then stirred to obtain a homogeneous clear slurry.

The composition is either (1) poured onto a smooth substrate or (2)
) to pile up. When the solvent is evaporated from the polymer composition, the polymer matrix containing the neutral TCNQ and CuTCNQ salts forms a transparent flexible film.

In general, a wide variety of matrix polymers and complexing agents can be used in this invention. In particular, the matrix polymers and complexing agents mentioned in the description of the multilayer enhancement aspect of the first embodiment are equally effective in this embodiment.

Similarly, the organic charge transfer salts used in this example are complexed from the non-limiting group of acceptor and donor materials described earlier in this specification, and the acceptor or donor molecules (organic salts are complexed from (of the same type) may be interspersed in the matrix polymer.

FIG. 4 is a schematic diagram of an optical storage system using either embodiment of the reinforced photosensitive material.

The optical writing beam (26) is attached to an organic charge transfer salt (20).
is focused on a specific location (28) on the film surface of the image. The light beam may be a high-intensity light source or a laser source such as an argon, CO□, or solid state laser that is focused to generate an optical field on the film surface. When used in a memory system, a well-known optical device is used to generate a light beam (26
) can be irradiated onto different locations on the surface of the organic charge transfer salt (20) to switch those locations from the first state to the second state, respectively. Turning the beam "on" or "off" at a particular location sets a logic state of "1" or "0" in the optical memory medium.

If a further increase in beam intensity or irradiation time is used, the light beam (26) can be irradiated onto the organic charge transfer salt (20) using well-known optical equipment.
Visible patterns can be “drawn” on top.

Once the data is stored on the organic charge transfer salt memory medium, spectroscopic equipment can then be used to determine whether a particular location in the organic film is in the first or second state. can.

A light source (32) also emits a low intensity reading light beam to detect said position (28) at an intensity significantly lower than the switching intensity.
It is also possible to irradiate any one of the positions. Optionally, a separate monochromatic or laser light source may be used.

Reflected light (34) from a selected position (28) on the film surface
) is collected and filtered by an optical filter (36) and then passed through a spectral intensity measuring device (38). The spectral measuring device (38) indicates the high or low amplitude of the reflected beam (34) that has passed through the filter (36), thereby indicating whether the position (28) is in the first or second state. That will happen.

The optical reading beam (32) is read using known optical equipment.
Multiple locations on the surface of the organic charge transfer salt (20), such as (
28) and (30)), it is possible to determine whether a particular position is in the first state or the second state, that is, whether the position is logical "1" or "0". You can decide whether

A thermal quencher can be used to quench (reverse) the topotactic reaction and return at least one of the plurality of locations on the surface of the enhanced organic charge transfer medium to a first or neutral state. It has been found that when a laser with an intensity below the switching threshold is focused on position (28) and this alignment is maintained for an appropriate period of time, the irradiated position is switched by the generated thermal energy and returns to the first state. Optionally, the same laser source (32) generates an optical heating beam of intensity less than or equal to the optical switching intensity, and this heating beam is irradiated using well-known optical equipment to create different regions on the organic charge transfer field surface (20). You can also delete a location.

It has been found that a variety of laser sources can be used to switch, read and erase enhanced optical storage media.

Figures 5 and 6 are two photographs taken consecutively.
It shows the optical recording and erasing process. The photograph shown in FIG. 5 shows 16 high contrast spots generated on a blue/black polycrystalline CuTCNQ film coated with a transparent polymer matrix interspersed with excess acceptor molecules. These spots were irradiated with 4 argon ion lasers.
It was made by operating at 88 nm. The photograph shown in FIG. 6 was taken of the same area as the photograph in FIG. 5 after chemical recombination of metallic copper and neutral acceptor molecules using an optically generated heat source.

As can be seen from the photograph in Figure 6, micro amounts of neutral TCNQ
High contrast spots associated with formation have disappeared.

A re-embodiment according to the invention also includes the two-state switching material described above and Bortinvar (Il).

S, Potever) and baler (T, 00Po
No. 603,717 (titled Multistate Optical Switching and Memories Using Bilateral Organic Charge Transfer Materials) taught in US Pat. In that patent application, an organic switching film comprises a plurality of two-state organic switching salts (such as those linked by chemical classes): 1. Alternatively, it is composed of a single amphoteric organic charge transfer complex. There are multiple acceptor and donor moieties in any multistate sinotic membrane. The enhancement mechanism according to the present invention takes advantage of the child state switching membrane by providing a secondary source of one or more moiety species in either a neutral or modified oxidation state interspersed within the polymer dispersion. can do.

The acceptor or donor moiety may itself exist as a separate molecule or may be chemically connected to another substance. The procedure for making the polymer dispersion is the same as taught herein.

In multilayer embodiments, the coating layer will have at least one moiety species (optionally together with a complexing agent) in a neutral or altered oxidation state interspersed within the matrix polymer. In the single reinforcing layer embodiment, the polymer dispersion is interspersed with microcrystals (or powdered microcrystals) of the child state switching material and one or more molecular species of the moiety in a neutral or altered oxidation state. It will have a polymer matrix that has been For child state non-erasable disks,
A switching dispersion can be made from at least two organic charge transfer salts interspersed within a polymer matrix. The switching dispersion may be coated onto a substrate or separately molded into a self-supporting substrate.

In view of the above description, it will be obvious that the invention is susceptible to many modifications.

Therefore, it is to be understood that the present invention may be practiced within the scope of the appended claims rather than as specifically described above.

[Brief explanation of drawings]

FIG. 1 is a graph of the Raman spectral hand of a two-state Cu TCNQ, FIG. 1a is a diagram showing the spectral bands of a neutral TCNQ, and FIG. FIG. 1c shows the spectral bands of CuTCNQ in the second or switched state, FIG. 2 is a general schematic diagram of a multilayer enhancement a according to the invention, and FIG. 3 is a single enhancement layer switching dispersion according to the invention. 4 is a general schematic diagram of the apparatus used to read/write/erase the enhanced switching material; FIG. 5 is a black and white photograph showing the 16 optically switched positions on the enhanced switching material; Figure 6 shows the improved erasure characteristics according to this invention.
This is a black and white photograph after the 16 switch positions in FIG. 5 have been optically erased. (10), (12)...Raman band, (
14)...Organic charge transfer base film, (16)...
...Supporting base, (18), (20)...
Polymer dispersion, (22)...Metal-TCNQ
, (24)...neutral TCNQ, (25)...
... complexing agent, (26) ... optical writing beam,
(28)...Specific position, (32)...
Light source, (34)...Reflected beam, (36)...
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J//Paltimore J Das and Charles Strilla (no address) Name The Johns Hopkins University J' 几 Annj7IReurin1ship Kitamura Patent Building 7, Contents of the amendment Mother Worker Pain Whip 1st shift-t- J-Lizono 4wakut1MJ line (to!2
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Claims (1)

Claims: 1. A molecule of at least one organic charge transfer substance switchable between at least two states having distinguishable and distinct optical properties responsive to optical energy and having at least one moiety. an organic charge transfer complex and a coating layer in which molecular species of the at least one moiety are interspersed, and which covers at least a portion of the organic charge transfer complex and enhances erasability of the organic charge transfer complex; A photosensitive medium consisting of 2. The photosensitive medium according to claim 1, wherein the coating layer is a polymer dispersion in which a complexing agent is interspersed. 3. The photosensitive medium according to claim 1, wherein the complex contains molecules of a single organic charge transfer salt consisting of a donor moiety and an organic electron acceptor moiety, and wherein the complex contains molecules of a single organic charge transfer salt consisting of a donor moiety and an organic electron acceptor moiety, and which are dispersed in the coating layer. A photosensitive medium, wherein at least one molecular species of the moiety is an oxidized molecular species of the organic electron acceptor moiety. 4. The photosensitive medium according to claim 1, wherein the complex contains molecules of a single organic charge transfer salt consisting of a donor moiety and an organic electron acceptor moiety, and wherein the complex contains molecules of a single organic charge transfer salt consisting of a donor moiety and an organic electron acceptor moiety, and which are dispersed in the coating layer. A photosensitive medium, wherein at least one molecular species of the donor moiety is a reduced molecular species of the donor moiety. 5. The photosensitive medium according to claim 1, wherein the complex contains at least two molecules of an organic charge transfer salt. 6. The photosensitive medium according to claim 1, wherein the complex contains molecules of at least one amphoteric charge transfer substance having one or more redox states. 7 consisting of a polymeric dispersion containing particles of at least one organic charge transfer material switchable between at least two states having distinctly different optical properties responsive to optical energy and having at least one moiety; , wherein particles of the organic charge transport material are interspersed in the polymer dispersion along with particles of the at least one moiety species that enhance erasing properties. 8. The photosensitive medium according to claim 7, wherein the polymer dispersion further has a complexing agent dispersed therein. 9. The photosensitive medium of claim 7, wherein the at least one organic charge transfer substance is a single type of organic charge transfer salt consisting of a donor moiety and an organic electron acceptor moiety; A photosensitive medium, wherein at least one molecular species of the moiety scattered throughout the body is an oxidized molecular species of the organic electron acceptor moiety. 10. The photosensitive medium of claim 7, wherein the at least one organic charge transfer substance is a single organic charge transfer salt consisting of a donor moiety and an organic electron acceptor moiety; A photosensitive medium, wherein at least one molecular species of the moiety scattered therein is a reduced molecular species of the donor moiety. 11. The photosensitive medium according to claim 7, wherein the at least one organic charge transfer substance comprises at least 2
A photosensitive medium comprising two organic charge transfer salts. 12. The photosensitive medium according to claim 7, wherein the at least one organic charge transfer substance comprises at least one amphoteric charge transfer substance having one or more redox states. . 13. a film of an organic charge transfer salt complexed from a donor and acceptor and capable of switching between first and second states having distinguishable and distinct optical properties, interspersed with neutral molecules of said acceptor; a coating layer that enhances the erasing properties of the film and covering at least a portion of the film. 14. The photosensitive medium according to claim 13, wherein the dispersion is a polymer matrix in which neutral molecules of the receptor are interspersed. 15. The photosensitive medium of claim 14, wherein the polymer matrix is at least partially transparent to light energy. 16. The photosensitive medium according to claim 13, wherein the dispersion has a complexing agent scattered therein. 17. The photosensitive medium according to claim 16, wherein the dispersion is a polymer matrix in which neutral molecules of the receptor and molecules of the complexing agent are interspersed. . 18. The photosensitive medium of claim 17, wherein the polymer matrix is at least partially transparent to light energy. 19. The photosensitive medium according to claim 16, wherein the photosensitive medium comprises a base layer of a supporting substrate, an intermediate layer of a film of an organic charge transfer salt, and neutral molecules of a receptor and a complexing agent interspersed therein. and an upper layer of a dispersion. 20. The photosensitive medium according to claim 19, wherein the wafer is disk-shaped. 21. The photosensitive medium according to claim 13, wherein the dispersion further has neutral molecular species of the donor dispersed therein. 22. The photosensitive medium according to claim 21, wherein the dispersion is a polymer matrix in which neutral molecules of the acceptor, neutral molecular species of the donor, and molecules of a complexing agent are interspersed. photosensitive medium. 23 A dispersion containing particles of an organic charge transfer salt complexed from a donor and an acceptor and capable of switching between first and second states having distinguishable and distinct optical properties, the organic charge transfer salt comprising: A photosensitive medium characterized in that salt particles are interspersed in the dispersion together with neutral molecules of the organic receptor. 24. The photosensitive medium according to claim 23, wherein the dispersion further has a complexing agent scattered therein. 25. The photosensitive medium according to claim 23, wherein the dispersion is a polymer matrix having particles of an organic charge transfer salt interspersed with neutral molecules of the receptor. Medium. 26. The photosensitive medium of claim 25, wherein the polymer matrix is at least partially transparent to light energy. 27. The photosensitive medium according to claim 24, wherein the dispersion is a polymer matrix having particles of an organic charge transfer salt interspersed with neutral molecules of the receptor and molecules of the complexing agent. A photosensitive medium characterized by: 28. The photosensitive medium of claim 27, wherein the polymer matrix is at least partially transparent to light energy. 29. The photosensitive medium according to claim 23, wherein the dispersion further has particles of the donor in a neutral oxidation state interspersed therein. 30. The photosensitive medium according to claim 23, wherein the dispersion comprises particles of the donor and particles of an organic charge transfer salt interspersed with neutral molecules of the acceptor of the complexing agent. A photosensitive medium characterized in that it is a polymer matrix comprising: 31. The photosensitive medium according to claim 23, 25, 27, or 30, wherein the organic charge transfer salt particles are microcrystalline. 32. A photosensitive medium comprising a polymeric dispersion interspersed with particles of at least one organic charge transfer material switchable between at least two states having distinctly different optical properties responsive to optical energy. 33. The photosensitive medium according to claim 32, wherein the particles of the at least one organic charge transfer substance are microcrystalline. 34. The photosensitive medium according to claim 32 or 33, wherein the polymer dispersion is a polymer matrix interspersed with particles of the at least one organic charge transfer substance. 35. The photosensitive medium according to claim 34, wherein the polymer dispersion forms a thin film on a supporting substrate. 36. The photosensitive medium of claim 32, wherein the at least one organic charge transfer material is a single type of organic charge transfer salt. 37. The photosensitive medium according to claim 32, wherein the at least one organic charge transfer substance comprises at least two
A photosensitive medium characterized in that it is one type of organic charge transfer salt. 38. The photosensitive medium according to claim 32, wherein the at least one organic charge transfer material is at least one amphoteric organic charge transfer material having at least one redox state. . 39. The photosensitive medium according to claim 14, 25 or 34, wherein the polymer matrix is polycarbonate polymethyl methacrylate (PMMA) polyacrylonitrile polyvinyl acetal poly(methyl-2-cyanoacrylate) poly(4,4) 'isopropyridine-diphenyl carbonate) (Lexan) polystyrene poly(pyromellitimide) (Kaptan) poly(vinyl fluoride) ethylcellulose poly(ethyl acrylate) poly(methyl acrylate). photosensitive medium. 40 The photosensitive medium according to claim 16, 19, 24 or 27, wherein the complexing agent is acetylacetone and its derivatives polyethylene oxide (Carbowax) polypropylene glycol polymer quaternary ammonium salt crown ether poly(butylene) 1. A photosensitive medium selected from the group consisting of: glycol) poly(epichlorohydrin) ethylenediaminetetratetraacetic acid (EDTA) nitrilotriacetic acid (NTA) dimethylglyoxime (DMG). 41 depositing on a substrate a film of an organic charge transfer salt complexed from a donor and an acceptor and capable of switching between first and second states having distinguishable and distinct optical properties; A method for producing a photosensitive medium, comprising the steps of: mixing a neutral molecule and a polymer to form a dispersion; and coating the dispersion on the film. 42. A method of manufacturing a photosensitive medium according to claim 41, characterized in that the coating step comprises spin-casting the dispersion onto the film. 43. A method for manufacturing a photosensitive medium according to claim 41, characterized in that in the coating step, the dispersion is formed into a thin layer, and then the thin layer is pressed onto a film. 44. A method for manufacturing a photosensitive medium according to claim 41, characterized in that in the coating step, the dispersion is brushed onto the film. 45. A method for producing a photosensitive medium according to claim 41, characterized in that, in the coating step, a dispersion is sprayed onto the film. 46. A method for producing a photosensitive medium according to claim 41, characterized in that in the coating step, the dispersion is dry coated onto a film. 47. The method for producing a photosensitive medium according to claim 41, wherein in the mixing step, the neutral molecules of the receptor, the polymer matrix, the complexing agent, and the solvent are mixed to form a dispersion. How to characterize it. 48. A method of manufacturing a photosensitive medium according to claim 47, characterized in that the solvent is evaporated after the coating step. 49. The method for producing a photosensitive medium according to claim 47, wherein in the mixing step, the neutral molecules of the acceptor, the polymer matrix, the complexing agent, and the solvent are further combined with the neutral molecular species of the donor. A method characterized by forming a dispersion by mixing. 50 particles of an organic charge transfer salt complexed from a donor and an acceptor and capable of switching between first and second states having distinct and distinct optical properties; and an auxiliary neutral molecule of said acceptor; A method for manufacturing a photosensitive medium, comprising the steps of: mixing with a polymer to form a dispersion; and forming the dispersion into a thin plate. 51. The method for producing a photosensitive medium according to claim 50, wherein in the mixing step, fine crystals of an organic charge transfer salt formed as a composite from the donor and acceptor are pulverized to form a powder; A method characterized by mixing and stirring the powdered organic charge transfer salt, the neutral molecules of the acceptor, and the polymer matrix to form a uniform dispersion. 52. The method for manufacturing a photosensitive medium according to claim 50, characterized in that in the thin plate forming step, the dispersion is coated on a substrate to form a thin layer of the dispersion on the substrate. how to. 53. A method for manufacturing a photosensitive medium according to claim 52, characterized in that the dispersion is coated on a substrate by spin casting. 54. A method of manufacturing a photosensitive medium according to claim 52, characterized in that the thin layer is further pressed onto a substrate. 55. A method for manufacturing a photosensitive medium according to claim 52, comprising: forming the dispersion into a thin layer, and then pressing the thin layer onto a substrate. 56. A method for producing a photosensitive medium according to claim 52, characterized in that the dispersion is coated on a substrate by brushing. 57. A method for producing a photosensitive medium according to claim 52, characterized in that the dispersion is coated onto a substrate by spraying. 58. A method for producing a photosensitive medium according to claim 52, characterized in that the dispersion is coated on a substrate by dry coating. 59. A method for producing a photosensitive medium according to claim 50, characterized by further adding a complexing agent to the dispersion and stirring uniformly. 60. A method for producing a photosensitive medium according to claim 50, further comprising adding an auxiliary neutral molecule of the donor to the dispersion,
A method characterized by uniform stirring. 61. A method for producing a photosensitive medium according to claim 50, characterized by further adding a solvent to the dispersion and stirring uniformly. 62. A method of manufacturing a photosensitive medium according to claim 61, characterized in that the solvent is evaporated from the dispersion after the dispersion is coated on a substrate. 63. The method for producing a photosensitive medium according to claim 47 or 51, wherein the matrix polymer is polycarbonate polymethyl methacrylate (PMMA) polyacrylonitrile polyvinyl acetal poly(methyl-2-cyanoacrylate) poly(4, 4'isopropyridine-diphenyl carbonate) (Lexan), polystyrene poly(pyromellitimide) (Kaptan), poly(vinyl fluoride), ethylcellulose poly(ethyl acrylate), poly(methyl acrylate). How to do it. 64. The method for producing a photosensitive medium according to claim 47 or 59, wherein the complexing agent is acetylacetone and its derivative polyethylene oxide (Carbowax) polypropylene glycol polymer quaternary ammonium salt crown ether poly(butylene glycol) ) poly(epichlorohydrin) ethylenediaminetetraacetic acid (EDTA) nitrilotriacetic acid (NTA) dimethylglyoxime (DMG).